The present invention relates to a clutch, a motor provided with the clutch, and a vehicle door opening and closing apparatus provided with the motor. The vehicle door opening and closing apparatus includes a vehicle slide door opening and closing apparatus and a vehicle backdoor opening and closing apparatus. The motor can serve as a drive source of the vehicle door opening and closing apparatus.
In recent years, there have been cases in which a motor vehicle has a slide door opening and closing apparatus. The slide door opening and closing apparatus has a motor device serving as a drive source for driving a slide door. The slide door opens and closes a door opening provided in a side portion of a vehicle body. The motor device is provided with a motor main body having a stator and an armature, and a speed reducing mechanism decelerating a rotation output by the motor main body. An output from the speed reducing mechanism drives the slide door.
It is necessary that the slide door opening and closing apparatus allow the slide door to open and close in accordance with a manual operation. Japanese Laid-Open Patent Publication No. 2002-327576 proposes a door opening and closing apparatus equipped with an electromagnetic clutch in an output shaft extending from the speed reducing mechanism.
In the publication mentioned above, when the motor device drives the slide door, the electromagnetic clutch is turned on. Accordingly, the electromagnetic clutch couples a rotating shaft extending from the armature to a worm wheel. Therefore, a rotating force output from the motor main body is transmitted to the worm wheel, and the slide door is automatically opened and closed in accordance with an electric motor control. In the case of manually operating the slide door, the electromagnetic clutch is turned off. Accordingly, the electromagnetic clutch shuts off the rotating shaft from the worm wheel, and allows the manual operation of the slide door.
However, it is complicated to arrange a wiring for supplying electricity to the electromagnetic clutch. Therefore, a mechanical clutch is desired. The mechanical clutch is demanded to be stably actuated at a time of coupling a drive shaft to a driven shaft and at a time of shutting off the drive shaft from the driven shaft.